This is directed to systems and methods for lumbar cerebrospinal fluid access, analysis, treatment, diversion and exchange.
The cerebrospinal fluid is a window to the functioning of the central nervous system. In humans, approximately 500 ml/day of cerebrospinal fluid is produced. The CSF circulates and traverses the brain and spinal cord several times a day and exhibits a craniocaudal flow pattern influenced by the cardiac cycle.
The cerebrospinal fluid can provide both diagnostic and therapeutic opportunities for treating brain and spinal cord injury and disease. Disease and injury of the cerebrospinal fluid may manifest as alterations in the production or absorption of cerebrospinal fluid, alterations in cerebrospinal flow and dynamics and/or the accumulation of toxins, metabolites and electrolytes in the fluid. Better diagnosis and therapeutics can therefore be achieved with systems and methods that improve the access, analysis, treatment, diversion and exchange of the cerebrospinal fluid.
Seemingly disparate brain and spinal disorders may be connected by disruptions in the normal cerebrospinal fluid. Thus systems and methods the improve the access, analysis, treatment, diversion and exchange of the cerebrospinal fluid can better address central nervous trauma, hemorrhage, infections, toxins, metabolic derangements, structural malformations, cystic lesions, benign and malignant masses, imbalances of cerebrospinal fluid production and absorption and flow, neurodegenerative diseases, pain syndromes and neuropsychiatric disorders, pharmacological studies on the CNS and experimental studies of the CSF dynamics.
The problem of chronic access for therapeutics to the central nervous system has heretofore been limited to subcutaneous cranioventricular reservoirs. The article “Implantable Devices for Chronic Access and Drug Delivery to the Central Nervous System” by Ommaya is incorporated herein by reference. It has been noted that these subcutaneous cranioventricular reservoirs are prone to infection, are prone to obstruction by biological material and can migrate unintentionally into brain regions important for speech, motor or vision, thereby creating new morbidity and mortality. In many ways, cerebrospinal fluid shunts are prone to the same problems. The article “Implanted ventricular shunts in the United States: The Billion-Dollar-A-Year Cost of the Hydrocephalus Treatment” by Patwardhan et al. is incorporated herein by reference.
I have also found that placement of this subcutaneous cranioventricular reservoir/pump requires general anesthesia which can be expensive. Additionally, placement of this type of device requires a cranial burrhole and ventriculostomy procedure which can be prone to complications and cosmetic concerns. The subcutaneous cranioventricular reservoir/pump also limits the volume of liquid that can be administered due to the sensitive cranial cerebrospinal fluid dynamics that occur within the fixed skull space.
The cranioventricular reservoir/pump only provides unidirectional flow of the cerebrospinal fluid due to the single catheter and reservoir/pump design, meaning that fluid can only be withdrawn or infused at a time and never simultaneously. Increasingly, the cerebrospinal fluid will be utilized to diagnose and treat disease, including the filtering of toxins and metabolites, which the present reservoir art will not allow. Furthermore, this art also lacks any monitoring, reporting and/or control ability. Finally, placement of this subcutaneous cranioventricular reservoir/pump necessitates repeating expensive imaging procedures such as CT or MRI. Repeat CT imaging can increase the radiation exposure to a patient.
Thus several advantages of one or more aspects are to provide a safer, faster and overall less expensive access to the cerebrospinal fluid. Other advantages of one or more aspects are to increase the comprehensive diagnostic and therapeutic capability. These and other advantages of one or more aspects will become apparent from a consideration of the ensuing description and accompanying drawings.